Reagent storage in an assay device

Abstract

The invention relates to methods for conducting binding assays in an assay device that includes one or more storage and use zone. The storage zones of the assay device are configured to house one or more reagents used in an assay conducted in the use zone of the device.

The invention claimed is: 
     
       1. A method of conducting an assay for an analyte of interest in a sample, wherein said method is conducted in an assay device comprising:
 (a) one or more reagent spaces comprising a storage zone comprising a storage surface to which two or more surface-reagent complexes are bound and thereby confined to said storage zone, said two or more surface-reagent complexes comprising a first surface-reagent complex and a second surface-reagent complex, said first surface-reagent complex comprising
 (i) a first reagent linked to a first targeting agent; 
 (ii) a first surface linked to a second targeting agent, and 
 
 said second surface-reagent complex comprising:
 (iii) a second reagent linked to a third targeting agent; and 
 (iv) a second surface linked to a fourth targeting agent, 
 
 wherein said first surface and said second surface are portions of the same storage surface, wherein said first reagent and said first surface and said second reagent and said second surface are linked, respectively, in said first and second surface-reagent complexes, via a selective releasable binding interaction between said first and second targeting agents and said third and fourth targeting agents, respectively, wherein said first reagent is released from said first surface-reagent complex by a first set of conditions that differs from a second set of conditions used to release said second reagent from said second surface-reagent complex; and 
 (b) one or more use zones each configured to use at least one of said first reagent and said second reagent in the assay for the analyte of interest in the sample; 
 said method comprising: 
 (x) introducing said sample to said one or more use zones; 
 (y) subjecting said storage zone to one of said first set of conditions and said second set of conditions that releases one of said first reagent and said second reagent from said surface-reagent complex; 
 (z) transferring one of said first reagent and said second reagent from said storage zone to said one or more use zones; and 
 (xx) conducting said assay in said one or more use zones with one of said first reagent and said second reagent. 
 
     
     
       2. The method of  claim 1  wherein said first set of conditions and said second set of conditions are selected from increased or decreased temperature, pH changes, applying an electrical potential, a change in ionic strength, competition, and combinations thereof. 
     
     
       3. The method of  claim 1  wherein one of said first set of conditions and said second set of conditions comprises increasing the temperature of said storage zone. 
     
     
       4. The method of  claim 3  wherein said increased temperature exceeds a melting temperature of said binding interaction. 
     
     
       5. The method of  claim 1  wherein said first reagent is a binding reagent that binds said analyte and said method further comprises detecting the amount of analyte bound to said binding reagent in said one or more use zones. 
     
     
       6. The method of  claim 5  wherein said first reagent comprises a detectable label and said detecting step comprises detecting the presence or absence of said detectable label in said one or more use zones. 
     
     
       7. The method of  claim 6  wherein said detectable label is an ECL label and said detecting step comprises detecting electrochemiluminescence emitted in said one or more use zones. 
     
     
       8. The method of  claim 1  wherein said storage zone and said one or more use zones are in fluidic communication along a fluid path and said transferring step (z) comprises transferring one of said first reagent and said second reagent from said storage zone via said fluid path to said one or more use zones. 
     
     
       9. The method of  claim 1  wherein said use zone comprises two or more assay regions each configured to use one of said first reagent and said second reagent in one or more assays conducted with said sample in said assay device, said method further comprising the step of conducting a plurality of assays in said one or more use zones with one of said first reagent and said second reagent. 
     
     
       10. The method of  claim 9  wherein said one or more use zones each comprise a first assay region configured to conduct an assay for a first analyte of interest in said sample and an additional assay region configured to conduct an assay for an additional analyte of interest in said sample, said method comprising:
 (x) introducing said sample to said one or more use zones; 
 (y) subjecting said storage zone to a condition that releases one of said first reagent and said second reagent from said surface-reagent complex; 
 (z) transferring one of said first reagent and said second reagent from said storage zone to said first assay region and said second assay region; 
 (xx) conducting said assay for said first analyte of interest and said assay for said additional analyte of interest in said first and second assay regions, respectively. 
 
     
     
       11. The method of  claim 10  wherein said assay for said first analyte of interest and said assay for said additional analyte of interest are conducted simultaneously. 
     
     
       12. The method of  claim 10  wherein said assay for said first analyte of interest and said assay for said additional analyte of interest are conducted sequentially. 
     
     
       13. The method of  claim 1 , wherein said first surface and said second surface have a three dimensional texture such that said first surface-reagent complex and said second surface-reagent complex, respectively, are capable of binding in at least a two-fold larger amount than the surface area of a flat surface. 
     
     
       14. The method of  claim 1 , wherein said assay device further comprises a fluid path in a fluidic network comprising one or more vent ports, wherein said storage zone, said one or more use zones, and said one or more vent ports are positioned in and in fluidic communication along said fluid path. 
     
     
       15. The method of  claim 1 , wherein said assay device is configured to conduct a multiplexed measurement. 
     
     
       16. A method of conducting an assay for an analyte of interest in a sample, wherein said method is conducted in a multi-well assay plate comprising a plate body comprising a plurality of assay wells and one or more reagent spaces defined in said plate body, wherein the one or more reagent spaces are in fluidic communication with one or more surrounding wells of said plurality of wells, wherein
 (a) said one or more reagent spaces comprise a storage zone comprising a storage surface to which two or more surface-reagent complexes are bound and thereby confined to said storage zone, said two or more surface-reagent complexes comprising a first surface-reagent complex and a second surface-reagent complex, said first surface-reagent complex comprising:
 (i) a first reagent linked to a first targeting agent; and 
 (ii) a first surface linked to a second targeting agent, and 
 said second surface-reagent complex comprising: 
 (iii) a second reagent linked to a third targeting agent; and 
 (iv) a second surface linked to a fourth targeting agent, 
 wherein said first surface and said second surface are portions of the same storage surface, and wherein said first reagent and said first surface and said second reagent and said second surface are linked, respectively, in said first and second surface-reagent complexes, via a selective releasable binding interaction between said first and second targeting agents and said third and fourth targeting agents, respectively, wherein said first reagent is released from said first surface-reagent complex by a first set of conditions that differs from a second set of conditions used to release said second reagent from said second surface-reagent complex; and 
 
 (b) said one or more surrounding wells are configured to use at least one of said first and second reagents in the assay for the analyte of interest in the sample; 
 said method comprising the following steps in the following order: 
 (x) introducing said sample to said one or more surrounding wells; 
 (y) subjecting said storage zone to said first set of conditions that selectively releases said first reagent from said surface-reagent complex; 
 (z) transferring said first reagent from said storage zone to said one or more surrounding wells; and 
 (xx) conducting said assay in said one or more surrounding wells with said first reagent, 
 wherein each of said first targeting agent is an antigen, the said second targeting agent is an antibody, said third targeting agent is an oligonucleotide and said fourth targeting agent is a complement, 
 wherein said first reagent is configured to detect a first analyte and said second reagent is configured to detect a second analyte, and 
 wherein said first reagent binds to said first analyte via a first releasable binding interaction, and said second reagent binds to the first analyte via a second releasable binding interaction, wherein the first releasable binding interaction releases at the first set of conditions that is different than the second set of conditions to release the second releasable binding interaction. 
 
     
     
       17. The method of  claim 16 , wherein said first surface and said second surface have a three dimensional texture such that said first surface-reagent complex and said second surface-reagent complex, respectively, are capable of binding in at least a two-fold larger amount than the surface area of a flat surface. 
     
     
       18. The method of  claim 16 , wherein said assay device further comprises a fluid path in a fluidic network comprising one or more vent ports, wherein said storage zone, said one or more use zones, and said one or more vent ports are positioned in and in fluidic communication along said fluid path. 
     
     
       19. The method of  claim 16 , wherein said assay device is configured to conduct a multiplexed measurement. 
     
     
       20. A method of conducting an assay with an assay device, wherein the assay device is a cartridge, for an analyte of interest in a sample, wherein the device comprises:
 (a) a storage zone comprising a storage surface to which two or more surface-reagent complexes are bound and thereby confined to said storage zone, said two or more surface-reagent complexes comprising a first surface-reagent complex and a second surface-reagent complex, said first surface-reagent complex comprising:
 (i) a first reagent linked to a first targeting agent; and 
 (ii) a first surface linked to a second targeting agent, and 
 said second surface-reagent complex comprising: 
 (iii) a second reagent linked to a third targeting agent; and 
 (iv) a second surface linked to a fourth targeting agent, 
 wherein said first surface and said second surface are portions of the same storage surface, and wherein said first reagent and said first surface and said second reagent and said second surface are linked, respectively, in said first and second surface-reagent complexes, via a selective releasable binding interaction between said first and second targeting agents and said third and fourth targeting agents, respectively, wherein said first reagent is released from said first surface-reagent complex by a first set of conditions that differs from a second set of conditions used to release said second reagent from said second surface-reagent complex; and 
 
 (b) one or more use zones configured to use at least one of said first and second reagents in the assay for the analyte of interest in the sample; 
 said method comprising the following steps in the following order: 
 (x) introducing said sample to said one or more storage zones; 
 (y) subjecting said storage zone to said first set of conditions that selectively releases said first reagent from said surface-reagent complex; 
 (z) transferring said first reagent from said storage zone to said one or more use zones; and 
 (xx) conducting said assay in said one or more use zones with said first reagent, 
 wherein each of said first targeting agent is an antigen, the said second targeting agent is an antibody, said third targeting agent is an oligonucleotide and said fourth targeting agent is a complement, 
 wherein said first reagent is configured to detect a first analyte and said second reagent is configured to detect a second analyte, and 
 wherein said first reagent binds to said first analyte via a first releasable binding interaction, and said second reagent binds to the first analyte via a second releasable binding interaction, wherein the first releasable binding interaction releases at the first set of conditions that is different than the second set of conditions to release the second releasable binding interaction. 
 
     
     
       21. The method of  claim 20  wherein said first set of conditions is selected from the group consisting of increased or decreased temperature, pH changes, applying an electrical potential, a change in ionic strength, competition, and combinations thereof and said second set of conditions is selected from the group consisting of increased or decreased temperature, pH change, application of an electrical potential, change in ionic strength, competition and combinations thereof, wherein said first and second set of conditions are different. 
     
     
       22. The method of  claim 20  wherein at least one of said first and second reagents is a binding reagent that binds said analyte and said method further comprises detecting the amount of analyte bound to said binding reagent in said one or more use zones. 
     
     
       23. The method of  claim 22  wherein said first reagent and said second reagent comprises a detectable label and said detecting step comprises detecting the presence or absence of said detectable label in said one or more use zones. 
     
     
       24. The method of  claim 23  wherein said detectable label is an electrochemiluminescence (ECL) label and said detecting step comprises detecting electrochemiluminescence emitted in said one or more use zones. 
     
     
       25. The method of  claim 20  wherein said storage zone and said one or more use zones are in fluidic communication along a fluid path and said transferring step (z) comprises transferring one of said first reagent and said second reagent from said storage zone via said fluid path to said one or more use zones. 
     
     
       26. The method of  claim 20  wherein said use zone comprises two or more assay regions each configured to use said first reagent and said second reagent in one or more assays conducted with said sample in said assay device, said method further comprising the step of conducting a plurality of assays in said one or more use zones with said first reagent and said second reagent. 
     
     
       27. The method of  claim 26  wherein said one or more use zones each comprise a first assay region configured to conduct an assay for a first analyte of interest in said sample and an additional assay region configured to conduct an assay for an additional analyte of interest in said sample, said method further comprising:
 (x) introducing said sample to said one or more use zones; 
 (y) subjecting said storage zone to the first set of conditions that is different than the second set of conditions that releases one of said first reagent and said second reagent from said surface-reagent complex; 
 (z) transferring one of said first reagent and said second reagent from said storage zone to said first assay region and said second assay region; 
 (xx) conducting said assay for the first analyte of interest and said assay for the additional analyte of interest in said first and second assay regions, respectively. 
 
     
     
       28. The method of  claim 27  wherein said assay for the first analyte of interest and said assay for the additional analyte of interest are conducted simultaneously. 
     
     
       29. The method of  claim 27  wherein said assay for the first analyte of interest and said assay for the additional analyte of interest are conducted sequentially. 
     
     
       30. The method of  claim 20 , wherein said first surface and said second surface have a three dimensional texture such that said first surface-reagent complex and said second surface-reagent complex, respectively, are capable of binding in at least a two-fold larger amount than the surface area of a flat surface. 
     
     
       31. The method of  claim 20 , wherein said assay device further comprises a fluid path in a fluidic network comprising one or more vent ports, wherein said storage zone, said one or more use zones, and said one or more vent ports are positioned in and in fluidic communication along said fluid path. 
     
     
       32. The method of  claim 20 , wherein said assay device is configured to conduct a multiplexed measurement.